Istrian Italians are an ethnic group in the northern Adriatic region of Istria, related to the Italian people of Italy. Historically they are descendants from the original Latinized population of Roman Istria, from the Venetian-speaking settlers who came to Istria during the time of the Republic of Venice, and from the South Slavic population in Istria that culturally assimilated to the Latins. Today, as a result of the Istrian exodus, the majority of Istrian Italians live outside of the Istrian peninsula; however, a significant Italian minority still lives in the Croatian County of Istria (6.92%) and in Slovenian Istria, where they are granted minority rights. According to the official Slovenian and Croatia censuses conducted in 2001 and 2002 their number is around 22,000. The Istrian diaspora, on the other hand, numbers more than 200,000 people.
The number of people resident in the Croatian part of Istria declaring themselves to be Italian nearly doubled between 1981 and 1991 (i.e. before and after the dissolution of Yugoslavia).
Historian Theodor Mommsen wrote that Istria (the X region of Roman Italia since Augustus) was fully romanized in the 5th century AD.
Between 500 and 700 AD, Slavs settled in Southeastern Europe (Eastern Adriatic), and their number ever increased, and with the Ottoman invasion Slavs were pushed from the south and east. This led to Italic people becoming ever more confined to urban areas, while some areas of the countryside were populated by Slavs, with exceptions in western and southern Istria which remained fully Romance-speaking.
By the 11th centuries, most of the interior mountainous areas of northern and eastern Istria (Liburnia) were inhabited by South Slavs, while the Romance population continued to prevail in the south and west of the peninsula. Linguistically, the Romance inhabitants of Istria were most probably divided into two main linguistic groups: in the north-west, the speakers of a Rhaeto-Romance language similar to Ladin and Friulian prevailed, while in the south, the natives most probably spoke a variant of the Dalmatian language.